1. Field of the Invention
The present invention relates to a tooth cleaner, and more particularly to a disposable prophy angle for an electric tooth polisher. The disposable prophy angle is compact and is easy to insert into and move around in a person's mouth to polish teeth.
2. Description of the Related Art
Electric tooth polishers are generally tools used by dentists to polish teeth.
With reference to FIG. 9, a conventional electric tooth polisher has a controller (70), a handle (80), a disposable prophy angle (90) and a head (93).
The controller (70) is connected to a power source and has a display and a switch.
The handle (80) is connected to the controller (70) through a cable and has a motor.
With further reference to FIGS. 10 and 11, the disposable prophy angle (90) is hollow, is connected to the handle and has a cavity, a bent distal segment (901), a driving shaft (91) and a driven cylinder (92). The driving shaft (91) is mounted in the cavity, is connected rotatably to the motor and has a gear (911) in the bent distal segment (901). The driven cylinder (92) rotatably engages the driving shaft (91) and has a gear (921) and a mount. The gear (921) of the driven cylinder (92) is mounted in the cavity, corresponding to the distal segment (901) and engages the gear (911) of the driving shaft (91). The mount extends out of the disposable prophy angle (90).
The head (93) is mounted to the mount of the driven cylinder (92) and rotates when driven by the motor. When the tooth polisher is used, the head (93) is coated with a special polishing paste. The head (93) rotates and contacts the teeth to polish the surface of the teeth.
However, the gears (911, 921) occupy a sizable amount of space in the cavity at the distal end (901) of the disposable prophy angle (90). This requires the distal segment (901) to be of a considerable size, which hinders the movement of the disposable prophy angle (90) in a person's mouth. The driving shaft (91) must also be perpendicular to the driven cylinder (92) due to the restriction of the angle of engagement of the gears (911, 921). In addition, the driving shaft (91), the driven cylinder (91) and the integral gears (911, 921) are made by injection molding, which adds to the cost. Furthermore, the gears (911, 921) may easily disengage from each other when the motor operates at high speed.
To overcome the shortcomings, the present invention provides a disposable prophy angle for an electric tooth polisher to mitigate or obviate the aforementioned problems.